Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Statistics and Mendel's Law of Independent Assortment

Name: Jovana
Status: student
Grade: other
Location: NY
Country: Sweden
Date: Winter 2013-2014


Question:
I am investigating the acceptance of 9:3:3:1 ratio in dihybrid cross (Mandels law of independent assortment). I am using 4 different genotypes of corn cobs (kernels): yellow and smooth, yellow and wrinkled, purple and smooth, purple and wrinkled. What could be my control variables? I just have 1 which is the same method of counting. Also I dont know which type of uncertainties I need to calculate. I was thinking to say that while counting I made uncertainy of +4 kernels, so if i do 4 trials, I will have uncertainty of +16 kernels. What do you think about that, and what more could I do?



Replies:
You did not say what grade level you were at, so I'll give you the college level answer I would give a student.

Since you are comparing your data an expected ratio, you no not need a control. The theoretical value is your "control". You need to use the chi squared test of goodness of fit to see if your actual data matches the theoretical expected within the bounds of probability. That is, any differences between the theoretical distribution and your data is due to random chance. Any good elementary statistics book should help you do the math.

Need any more help, get hold of me directly.

Bob Avakian Oklahoma State University Institute of Technology (OSUIT)



Click here to return to the Mathematics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 223
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: November 2011
Weclome To Newton

Argonne National Laboratory